JP2015151305A - Optical component and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical component including a glass layer that contains a phosphor having low heat resistance, in which performances of the phosphor are maintained while moisture resistance is ensured.SOLUTION: An optical component 10 includes a light-transmitting substrate 12, a first layer 14, and a second layer 16. The light-transmitting substrate 12 is made of a light-transmitting ceramic material. The first layer 14 comprises a first phosphor and a first glass and is formed to wholly cover an upper surface of the light-transmitting substrate 12. The second layer 16 is made of a second glass having a softening point higher than that of the first glass and is formed to wholly cover an upper surface of the first layer 14. The first phosphor less likely degrades when subjected to the temperature of the softening point of the first glass compared to a case when the first phosphor is subjected to the temperature of the softening point of the second glass. The heat-resistant temperature of the first phosphor is preferably higher than the softening point of the first glass and lower than the softening point of the second glass.

Description

  The present invention relates to an optical component and a manufacturing method thereof.

  2. Description of the Related Art Conventionally, a light emitting color conversion member that converts part of blue light emitted from a blue light source into yellow light and combines it with the remaining blue light to produce white light is known. For example, Patent Document 1 discloses a material in which an oxide phosphor is dispersed in glass having a softening point higher than 500 ° C. On the other hand, it is known that a translucent ceramic is a ceramic but has translucency and good thermal conductivity. For example, Patent Document 2 discloses a method for producing translucent alumina used in a light emitting container or the like.

Japanese Patent No. 4158012 JP 2006-160595 A

  With reference to Patent Documents 1 and 2, it can be considered that a structure in which a glass in which an oxide-based phosphor is dispersed and a light-transmitting substrate are laminated is used as a luminescent color conversion member. If it carries out like this, the blue light emitted from a blue light source with the former glass can be converted into the light of a desired color, and heat can be dissipated with the latter translucent board | substrate.

  By the way, glass has a thing with a low softening point, and a high thing. In general, a glass having a low softening point is inferior in moisture resistance to a glass having a high softening point, and when used in a high-temperature and high-humidity environment, defects such as cloudiness may occur. Therefore, in consideration of moisture resistance, it is preferable to use a glass having a high softening point. At that time, if an oxide phosphor having high heat resistance, even if it is mixed with glass having a high softening point and molded and then fired at a high firing temperature corresponding to the softening point, there is little risk of deterioration.

  However, when manufacturing a glass layer in which a phosphor having low heat resistance in the atmosphere such as a non-oxide phosphor is dispersed, the phosphor particles are mixed with a glass powder having a high softening point and then molded. When firing at a high firing temperature corresponding to the softening point, the phosphor deteriorates, and the performance may not be sufficiently exhibited. On the other hand, when such a phosphor with low heat resistance is mixed with glass with a low softening point and then fired at a low firing temperature corresponding to the softening point, the phosphor is unlikely to deteriorate, but the glass with a low softening point is exposed to humidity. Since it is weak, there is a risk of malfunction when used in a hot and humid environment.

  The present invention has been made in order to solve such problems, and in an optical component having a glass layer containing a phosphor having low heat resistance, while maintaining moisture resistance, the performance of the phosphor is also maintained. The main purpose.

The optical component of the present invention is
A translucent substrate;
A first layer provided on the translucent substrate and including a first phosphor and a first glass;
A second layer including a second glass provided to cover at least the upper surface of the first layer and having a higher softening point than the first glass;
With
The first phosphor is less susceptible to deterioration when exposed to the softening point temperature of the first glass than when exposed to the softening point temperature of the second glass.

  This optical component can dissipate heat from the light source by the translucent substrate. Further, light emitted from the light source can be converted into light of a different color. Further, since the first layer includes the first glass having a softening point lower than that of the second glass, the first layer does not have sufficient moisture resistance, but the second layer covering the upper surface of the first glass is Since the second glass has a higher softening point than the first glass, it has sufficient moisture resistance. Therefore, as an optical component, sufficient moisture resistance is ensured by the second layer. Furthermore, the first phosphor has a property that it is less likely to deteriorate when exposed to the temperature of the softening point of the first glass than when exposed to the temperature of the softening point of the second glass. Therefore, when the first phosphor is fired at a high firing temperature corresponding to the softening point of the second glass (for example, a temperature equal to or higher than the softening point of the second glass), the performance of the first phosphor is likely to deteriorate. However, in the present invention, the first phosphor is subjected to a low firing temperature corresponding to the softening point of the first glass where the first glass powder softens and melts (for example, a temperature not lower than the softening point of the first glass and lower than the softening point of the second glass, Since the firing is preferably performed in advance at a temperature equal to or lower than the heat resistant temperature of the first phosphor, the performance of the first phosphor is unlikely to deteriorate. Further, when the second glass is fired, the first glass is exposed to a high temperature corresponding to the softening point of the second glass in a state where the form of the first glass is not a powder but a solid, and thus the surface area of the first glass that receives heat. Becomes smaller. Therefore, the melting speed of the first glass is slowed down, and even if the first phosphor is exposed to the firing temperature of the second glass having a higher softening point than the first glass, the deterioration of the first phosphor can be suppressed. Further, since the first phosphor particles are melted with the first glass to cover the first phosphor, the first phosphor particles are effectively prevented from coming into contact with the atmosphere, and the softening point of the first glass. It can be fired above the softening point of the high second glass. From the above, according to the optical component of the present invention, although the glass layer containing the phosphor having low heat resistance is provided, the effect of maintaining the performance of the phosphor while ensuring the moisture resistance can be obtained. .

  In determining the color of the first phosphor, the color after the light emitted from the light source passes through the optical component of the present invention may be determined as appropriate. Further, the first phosphor may be one type or two or more types, and in the case of two or more types, the same color phosphors or different color phosphors may be used. May be. Further, the first layer may contain a phosphor having higher heat resistance than the first phosphor in addition to the first phosphor. In that case, the phosphor with high heat resistance may be the same color as the first phosphor or a different color.

  In the optical component of the present invention, the first phosphor may have a heat resistant temperature higher than the softening point of the first glass and lower than the softening point of the second glass. In this specification, the heat resistant temperature of the phosphor refers to a maximum temperature at which the internal quantum efficiency of the phosphor after the heat treatment does not decrease by 40% or more compared to the internal quantum efficiency of the phosphor before the heat treatment.

  In the optical component of the present invention, the first phosphor may be a non-oxide phosphor or a nitride phosphor. In general, non-oxide phosphors and nitride phosphors have lower heat resistance in the atmosphere than oxide phosphors. Therefore, when a phosphor containing a non-oxide phosphor or a nitride phosphor is used as the first phosphor, it is highly significant to adopt the configuration of the present invention.

  In the optical component of the present invention, the second layer may include a second phosphor having higher heat resistance than the first phosphor. This increases the degree of freedom in designing the color of light after passing through the optical component. Since the second layer includes the second glass having a softening point higher than that of the first glass, the second phosphor is fired at a high firing temperature corresponding to the softening point of the second glass. Has high heat resistance, so its performance is unlikely to deteriorate. As such a second phosphor, an oxide-based phosphor may be used.

  In the optical component of the present invention, the second layer may cover the upper surface and side surfaces of the first layer. By so doing, not only the top surface of the first layer but also the side surfaces are not exposed to the outside, so the moisture resistance of the optical component is further improved.

  An optical component according to the present invention includes a third glass that is provided between the translucent substrate and the second layer so as to surround the periphery of the first layer and has a softening point higher than that of the first glass. Three layers may be provided. By so doing, not only the top surface of the first layer but also the side surfaces are not exposed to the outside, so the moisture resistance of the optical component is further improved. Such a third layer may contain a first phosphor. In this case, since the first phosphor is contained in the first layer and the third layer as compared with the case where the first phosphor is contained only in the first layer on the light-transmitting substrate, The color from the light source can be converted. In this case, the softening points T1 to T3 of the first to third glasses are preferably in a relationship of T1 <T3 ≦ T2. For example, T1 may be 300 to 800 ° C, and T2 and T3 may be 500 to 1000 ° C.

  In the optical component of the present invention, the glass may be formed by baking white glass powder. White glass powder contains bubbles, and when this is baked, there is a high possibility that pores will remain in the glass, and the effect of reducing thermal stress due to light dispersion effects and thermal strain generated between each layer There is.

The manufacturing method of the optical component of the present invention is as follows:
(A) A first paste containing a first phosphor and a first glass is coated on a light-transmitting substrate, and the first paste is fired at a firing temperature corresponding to the softening point of the first glass. A layering process;
(B) applying a second paste containing a second glass having a softening point higher than that of the first glass so as to cover at least the upper surface of the first layer, and at a firing temperature corresponding to the softening point of the second glass; Baking the two pastes into a second layer;
Including
As the first phosphor, a phosphor that is less likely to deteriorate when exposed to the softening point temperature of the first glass than when exposed to the softening point temperature of the second glass is used. is there.

  According to this method for manufacturing an optical component, the above-described optical component can be manufactured relatively easily. Further, in step (b) of this production method, the first layer containing the first phosphor is also fired at a firing temperature corresponding to the softening point of the second glass (higher than the firing temperature corresponding to the softening point of the first glass). It is processed. However, since the first phosphor is confined in the first layer, it is difficult to be affected by the atmospheric atmosphere at a high temperature. Further, since the first phosphor particles are effectively prevented from being melted in the first glass and coming into contact with the atmosphere, the atmosphere is maintained even when the first phosphor particles are subjected to the heat treatment temperature of the second glass. Can be effectively prevented. Therefore, even after the end of the step (b), the first phosphor contained in the first layer is hardly damaged.

  In the method for producing an optical component of the present invention, the first phosphor may have a heat resistant temperature higher than the softening point of the first glass and lower than the softening point of the second glass, and is a non-oxide phosphor. There may be. In general, since non-oxide phosphors have lower heat resistance than oxide phosphors, it is highly meaningful to employ the production method of the present invention when a non-oxide phosphor is used as the first phosphor. Further, the second paste may contain a second phosphor (for example, an oxide-based phosphor) having higher heat resistance than the first phosphor. This increases the degree of freedom in designing the color of light after passing through the optical component. Further, in the second layer forming step, the second paste may be applied so as to cover the upper surface and side surfaces of the first layer. By so doing, not only the top surface of the first layer but also the side surfaces are not exposed to the outside, so that the moisture resistance of the optical component is further improved.

  In the method for producing an optical component of the present invention, after the step (a), a third paste containing a third glass having a softening point higher than that of the first glass is formed on the light-transmitting substrate, A third layer forming step is performed in which the third paste is baked at a baking temperature corresponding to the softening point of the third glass to form a third layer, and then the step (b) is performed. The second layer may be formed so as to cover the upper surfaces of the first layer and the third layer. By so doing, the side surface of the first layer is also covered with the third layer without being exposed to the outside, so that the moisture resistance of the optical component is further improved. Such a third layer may contain a first phosphor. In this case, since the first phosphor is contained in the first layer and the third layer as compared with the case where the first phosphor is contained only in the first layer on the light-transmitting substrate, The color from the light source can be converted. In this case, since the first phosphor is fired at a firing temperature higher than the softening point of the first glass corresponding to the softening point of the third glass, the performance is deteriorated compared to the first phosphor in the first layer. However, if the light emitting area related to the third layer is designed to be smaller than that of the first layer, the influence is limited. Note that the third glass may be the same as the second glass.

A sectional view of optical component 10 of a 1st embodiment. Sectional drawing of the optical component 20 of 2nd Embodiment. Sectional drawing of the optical component 30 of 3rd Embodiment. Sectional drawing of the optical component 40 of 4th Embodiment. Sectional drawing of the optical component 50 of the comparative example 1. FIG. The block diagram of the apparatus which measures chromaticity of a sample.

[First Embodiment]
FIG. 1 is a cross-sectional view of the optical component 10 of the first embodiment. The optical component 10 includes a translucent substrate 12, a first layer 14, and a second layer 16.

The translucent substrate 12 is a substrate made of a translucent ceramic material. The thickness of the translucent substrate 12 is preferably 0.01 mm or more and 5 mm or less, for example. The light-transmitting substrate 12 preferably contains a very small amount of pores inside, for example, 1 ppm to 1000 ppm by volume. The kind of the translucent ceramic material is not particularly limited, and examples thereof include alumina, aluminum nitride, YAG, Si ₃ N ₄ , quartz, sapphire, and hard glass (for example, Pyrex (registered trademark)). Translucent alumina is preferred. The average particle diameter of the translucent alumina crystal is preferably 0.5 to 50 μm.

  The first layer 14 includes the first phosphor and the first glass, and is provided so as to cover the entire upper surface of the translucent substrate 12. The second layer 16 is made of a second glass having a softening point and moisture resistance higher than those of the first glass, and is provided so as to cover the entire upper surface of the first layer 14. The first phosphor is less susceptible to degradation when exposed to the temperature of the softening point of the first glass than when exposed to the temperature of the softening point of the second glass. The heat resistant temperature of the first phosphor is higher than the softening point of the first glass and lower than the softening point of the second glass. The thickness of the first layer 14 and the second layer 16 is preferably 5 to 500 μm. The average particle diameter of the phosphor particles is preferably 50 μm or less, more preferably 2 to 30 μm, and even more preferably 5 to 30 μm.

  Next, a usage example of the optical component 10 will be described. The optical component 10 converts a part of light (light source light) emitted from the light source into light of another color, and combines the converted light and the remaining light source light to obtain light of a desired color. it can. In this case, for example, a light source may be disposed on the light transmissive substrate 12 side of the optical component 10, or a light source may be disposed on the second layer 16 side of the optical component 10. In the former case, the diffusion of the light source light to the first phosphor increases. In the latter case, the diffusion of the light mixed with the light converted into the different color by the first phosphor and the light source light is increased, and the heat generated by the optical component can be efficiently dissipated by the translucent substrate 12. it can. The first layer 14 may include another phosphor in addition to the first phosphor. As another phosphor, for example, an oxide phosphor or a non-oxide phosphor may be used. Another phosphor may be included in the second layer 16 instead of being included in the first layer 14. When a plurality of types of phosphors are used, the phosphors may be selected so that the light source light becomes light of a desired color after passing through the optical component 10.

  The light source is not limited to blue, but may be green or red. However, when a blue LED is used, the optical component 10 converts part of the blue light emitted from the blue LED into light of another color. Alternatively, the phosphor may be selected so as to be combined with the remaining blue light to become white light. In this case, a blue LED excitation phosphor is used as the phosphor. Blue LED excitation phosphors include oxide phosphors and non-oxide phosphors. Each representative example is shown below for each color.

・ Oxide-based phosphor Yellow (Y, Gd) ₃ Al ₅ O ₁₂ : Ce ³⁺
Tb ₃ Al ₅ O ₁₂ : Ce ³⁺
Red (Sr, Ba) ₃ SiO ₅ : Eu ²⁺
Green Y ₃ (Al, Ga) ₅ O ₁₂ : Ce ³⁺
(Ba, Sr) ₂ SiO ₄ : Eu ²⁺
・ Non-oxide phosphor Yellow CaGa ₂ S ₄ : Eu ²⁺
Ca-α-Sialon: Eu ²⁺
Red (Sr, Ca) S: Eu ²⁺
(Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺
Green SrGa ₂ S ₄ : Eu ²⁺
β-Sialon: Eu ²⁺

  What is necessary is just to select the 1st fluorescent substance in the 1st layer 14 from the non-oxide type fluorescent substance mentioned above, for example. When another phosphor other than the first phosphor is included in the first layer 14 (that is, when phosphors are mixed), for example, it may be selected from the oxide phosphors described above, You may select from oxide type fluorescent substance. When the phosphors are mixed in this way, the red phosphor, the green phosphor, and the blue light emitted from the light source may be mixed to make white, or the yellow phosphor and the blue light emitted from the light source may be mixed to make white. Good. The former is more preferable than the latter because it has higher color rendering (that is, more red than blue) and a wider color reproduction range (that is, a wider wavelength range is included). By adjusting the amount of the first phosphor in the first layer 14, the emission color determined by the light source and the first phosphor can be arbitrarily changed. Although blue is exemplified as the light source, it is preferable to select a phosphor suitable for each light source even when a red or green light source is used.

  Moreover, the typical example of the glass with a low softening point which can be used as 1st glass and the glass with a high softening point which can be used as 2nd glass is shown below with the softening point Ts. In the following examples, a glass having a Ts of 600 ° C. or lower is a glass having a low softening point, and a glass having a Ts of 700 ° C. or higher is a glass having a high softening point. The glass may contain lead oxide in order to lower the softening point, but it is preferable not to include it in consideration of environmental problems. The glass is preferably colorless and transparent. However, if there is no problem in optical design, the glass can be colored and transparent. Depending on the size, the glass can be used even if it is not transparent and contains a crystalline material.

-Glass with a low softening point Zn-B-Si-Na-O (Ts = 560 ° C.)
P—Sr—O (Ts = 344 ° C.)
Pb—B—Zn—Al—Si—O (Ts = 445 ° C.)
・ Glass with a high softening point Ca—Ba—Si—O (Ts = 850 ° C.)
Ba—B—Al—Si—O (Ts = 783 ° C.)
B-Si-O (Ts = 762 ° C)
The oxide phosphors enumerated above have heat resistance equal to or higher than the softening point of the glass having a high softening point mentioned here. In addition, the non-oxide phosphors enumerated above have heat resistance equal to or higher than the softening point of the glass having a low softening point and less than the softening point of the glass having a high softening point.

  Next, the manufacturing method of the optical component 10 is demonstrated. First, a first paste containing a first phosphor and a first glass is applied onto the light-transmitting substrate 12, and the first paste is fired at a firing temperature corresponding to the softening point of the first glass. (Step (a)). Next, a second paste containing the second glass is applied so as to cover the upper surface of the first layer 14, and the second paste is fired at a firing temperature corresponding to the softening point of the second glass to form the second layer 16. The optical component 10 is obtained (step (b)).

  Here, the firing temperature of the step (a) may be, for example, 0 to 200 ° C. higher than the softening point of the first glass. The first phosphor preferably has a heat resistant temperature equal to or higher than the firing temperature in the step (a). However, in the case of using the first phosphor whose heat-resistant temperature is lower than the firing temperature in the step (a), if the firing process is completed in a short time, the performance deterioration of the first phosphor can be minimized. it can. Moreover, what is necessary is just to make the calcination temperature of a process (b) 0-200 degreeC higher than the softening point of 2nd glass, for example. The firing treatment in each step is preferably performed so that the thermal history (approximately the same as the product of the firing temperature and the firing time) is as small as possible. The firing time for each step may be appropriately set according to the firing temperature and the heat-resistant temperature, but it is preferable to set the firing time to be shorter as the firing temperature is higher in consideration of reducing the thermal history. Moreover, the one where the temperature increase rate and temperature decrease rate are larger is preferable. The furnace to be used may be a single furnace, but a belt furnace (in a continuous furnace having a plurality of zones in which different temperatures can be set, each zone is moved by a belt carrying a processing object). May be used. Use of a belt furnace is preferable because the time required for temperature increase and decrease is shortened. The relationship between the softening point T1 of the first glass and the softening point T2 of the second glass may be T2> T1, but preferably 100 ° C. ≦ T2-T1 ≦ 500 ° C., and 200 ° C. ≦ T2-T1. More preferably, ≦ 400 ° C. For example, T1 may be 300 to 800 ° C. and T2 may be 500 to 1000 ° C. In the step (b), since the first layer 14 is heated again, it is preferable to design the entire light emission in consideration of characteristics that change due to reheating of the first layer 14. For example, when recrystallization of the first layer 14 is accompanied by crystallization of glass in the first layer or generation of bubbles, it is preferable to design the entire light emission in consideration of the characteristics.

  In the step (a), the volume ratio of phosphor to glass (each component volume = each component weight / specific gravity) is preferably phosphor / glass = 95/5 to 5/95. Although it depends on the amount of light source, the amount of phosphor necessary to obtain a predetermined wavelength is a substantially constant value. For example, the thickness of the first layer 14 is increased if the value of phosphor / glass is small, If the value of phosphor / glass is large, it may be thinned. When the glass is smaller than 5 by the phosphor / glass volume ratio, it becomes difficult to effectively bind the phosphor particles to the translucent substrate. When the glass is larger than 95, the thickness of the phosphor layer is increased and the film is formed. Becomes difficult. More preferably, the phosphor / glass volume ratio is 90/10 to 30/70.

  According to the optical component 10 described in detail above, heat from the light source can be dissipated by the translucent substrate 12. Further, light emitted from the light source can be converted into light of a different color. The first layer 14 includes the first glass having a softening point lower than that of the second glass. Therefore, the first layer 14 does not have sufficient moisture resistance, but the second layer 16 covers the upper surface of the first glass. Since the second glass has a softening point higher than that of the first glass, it has sufficient moisture resistance. Therefore, as the optical component 10, sufficient moisture resistance is ensured by the second layer. Furthermore, the first phosphor has a property that it is less likely to deteriorate when exposed to the temperature of the softening point of the first glass than when exposed to the temperature of the softening point of the second glass. Therefore, when the first phosphor is fired at a high firing temperature corresponding to the softening point of the second glass, the performance is likely to deteriorate, but here, the first phosphor is fired at a low firing temperature corresponding to the softening point of the first glass. Therefore, the performance is not easily deteriorated. Further, when the first phosphor particles are dispersed in the glass layer in which the first glass is melted, contact with the atmosphere can be effectively prevented even when the first phosphor particles are subjected to the heat treatment temperature of the second glass. Is. Therefore, although the optical component 10 includes the first layer 14 including a phosphor having low heat resistance, the performance of the phosphor can be maintained while ensuring moisture resistance.

[Second Embodiment]
FIG. 2 is a cross-sectional view of the optical component 20 of the second embodiment. The optical component 20 includes a translucent substrate 22, a first layer 24, and a second layer 26. In the optical component 20, compared to the optical component 10 of the first embodiment, the first layer 24 covers not the entire upper surface of the translucent substrate 22 but the outer peripheral edge, and the second layer 26 includes: The difference is that it covers the upper surface and the side surface of the first layer 24, but the rest is the same as the optical component 10.

  Although the optical component 20 described above includes the first layer 24 including the phosphor having low heat resistance, like the optical component 10, the performance of the phosphor can be maintained while ensuring the moisture resistance. Further, while the optical component 10 has the side surface of the first layer 14 exposed to the outside, the optical component 20 has further improved moisture resistance because the side surface of the first layer 24 is not exposed to the outside. .

[Third Embodiment]
FIG. 3 is a cross-sectional view of the optical component 30 of the third embodiment. The optical component 30 includes a translucent substrate 32, a first layer 34, a second layer 36, and a third layer 38. Compared with the optical component 10 of the first embodiment, the optical component 30 includes a first layer 34 on the upper surface of the translucent substrate 32 except the outer peripheral edge, and an annular third layer 38 on the outer peripheral edge. The second embodiment is the same as the optical component 10 except that it is covered and the second layer 36 covers the top surfaces of the first layer 34 and the third layer 38. The third layer 38 is a layer including a third glass (which may be the same material as the second glass) having a softening point higher than that of the first glass and the first phosphor.

  A method for manufacturing the optical component 30 will be described. First, in the same manner as in step (a) of the first embodiment, the first layer 34 is formed on the upper surface of the translucent substrate 32 except for the outer peripheral edge. Next, a third paste containing the third glass and the first phosphor is applied to the outer peripheral edge of the upper surface of the translucent substrate 32 so as to cover the side surface of the first layer 34, and the softening point of the third glass. The third paste is fired at a firing temperature corresponding to the above to form the third layer 38. The firing temperature at this time is 0 to 200 ° C. higher than the softening point of the third glass. Thereafter, the step (b) of the first embodiment is performed to form the second layer 36 so that the second layer 36 covers the upper surfaces of the first layer 34 and the third layer 38. The third layer 38 may be fired at the same time as the second layer 36 after the first layer 34 is fired, or before the second layer 36, the firing temperature of the first layer to the second layer. You may bake between these baking temperatures.

  Although the optical component 30 described above includes the first layer 34 including a phosphor having low heat resistance, like the optical component 10, the performance of the phosphor can be maintained while ensuring moisture resistance. Further, in the optical component 10, the side surface of the first layer 14 is exposed to the outside, whereas in the optical component 30, the side surface of the first layer 34 is not exposed to the outside, so that the moisture resistance is further improved. . In addition, since the first phosphor is included in the first layer 34 and the third layer 38 as compared with the case where the first phosphor is included only in the first layer 34, the color from the light source can be changed over a wide range. Can be converted.

  The third layer 38 of the optical component 30 may be a layer that does not contain a phosphor, that is, a layer formed only from the third glass. In this case, only the first layer 34 can convert the color from the light source, but since the side surface of the first layer 34 is not exposed to the outside, the moisture resistance is further improved as compared with the optical component 10. .

[Fourth Embodiment]
FIG. 4 is a cross-sectional view of the optical component 40 of the fourth embodiment. The optical component 40 includes a translucent substrate 42, a first layer 44, and a second layer 46. The optical component 40 is different from the optical component 20 of the second embodiment in that the second layer 46 includes a second phosphor having higher heat resistance than the first phosphor. Others are the same as the optical component 20. The second phosphor is fired at a high firing temperature corresponding to the softening point of the second glass. However, since the heat resistance is high, the performance is hardly deteriorated. As such a second phosphor, an oxide-based phosphor may be used. The heat resistant temperature of the second phosphor is preferably higher than the softening point of the second glass, and more preferably higher than the firing temperature in the above-described step (b).

  Although the optical component 40 described above includes the first layer 24 including a phosphor having low heat resistance, like the optical component 20, the performance of the phosphor can be maintained while ensuring moisture resistance. In addition, since the second layer 46 includes the second phosphor, the degree of freedom in designing the light color is higher than that of the optical component 20 in which the second layer 26 does not include the phosphor.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, in each of the embodiments described above, one type of first layer 14 is provided on the upper surface of the translucent substrate 12, but the upper surface of the translucent substrate 12 is divided into a plurality of sections, and the types are different for each section. A glass paste containing phosphor powder may be applied to provide a plurality of types of first layers in the same plane.

[Example 1]
Oxidized red phosphor (Sr, Ba) ₃ SiO ₅ : Eu ²⁺ and non-oxide green phosphor β-Sialon: Eu ²⁺ mixed in a volume ratio of 1: 1 to soften the phosphor powder Zn—B—Si—Na—O (Ts = 560 ° C.), which is a low-point glass, was weighed so that its volume ratio was 30%, and these were mixed. To 100 parts by weight of the mixed powder, 15 parts by weight of butyral resin was added, and terpineol was mixed as a solvent to obtain a first paste. Similarly, 20 parts by weight of butyral resin is added to 100 parts by weight of Ba—B—Al—Si—O (Ts = 783 ° C.) glass 1) which is a glass having a high softening point, and terpineol is added. A second paste was prepared by mixing as a solvent.

  A paste layer having a length of 25 mm, a width of 25 mm, and a height of 0.05 mm is formed on a translucent alumina substrate (average particle diameter: 20 μm) having a length of 30 mm, a width of 30 mm, and a thickness of 1 mm by screen printing using the first paste. The paste layer was formed and fired in the atmosphere to form a first layer. As firing conditions, the temperature was raised to 600 ° C. at a temperature raising rate of 50 ° C./mm, held at 600 ° C. for 10 minutes, and lowered at a temperature lowering rate of 50 ° C./mm. Next, a paste layer having a length of 28 mm, a width of 28 mm, and a height of 0.1 mm is formed on the first layer by screen printing so as to cover the upper surface and the side surface of the first layer. Was fired in the atmosphere to form a second layer. As firing conditions, the temperature was increased to 800 ° C. at a temperature increase rate of 100 ° C./min, held at 800 ° C. for 5 minutes, and the temperature was decreased at a temperature decrease rate of 100 ° C./min. Thereby, the optical component 20 shown in FIG. 2 was obtained. Ten optical components 20 were produced.

[Comparative Example 1]
In Example 1, ten optical components 50 shown in FIG. 5 in which only the first layer was formed and the second layer was omitted were produced.

[Evaluation]
For Example 1 and Comparative Example 1, the initial chromaticity (= chromaticity diagram (CIE1931) y value) was measured using a fluorescence spectrophotometer (manufactured by JASCO Corporation, FP-8300) and a φ60 mm integrating sphere with the arrangement shown in FIG. After the measurement, it was placed in a high-temperature and high-humidity tank having a temperature of 85 ° C. and a humidity of 85%, and the chromaticity change was observed. Table 1 shows the number of occurrences of the substrate with a change of ± 5% or more with respect to the initial chromaticity y value. From Table 1, it was confirmed that Example 1 of the present invention was superior in moisture resistance as compared with Comparative Example 1.

DESCRIPTION OF SYMBOLS 10 Optical component, 12 Translucent substrate, 14 1st layer, 16 2nd layer, 20 Optical component, 22 Translucent substrate, 24 1st layer, 26 2nd layer, 30 Optical component, 32 Translucent substrate, 34 1st layer, 36 2nd layer, 38 3rd layer, 40 Optical component, 42 Translucent substrate, 44 1st layer, 46 2nd layer, 50 Optical component.

Claims (12)

A translucent substrate;
A first layer provided on the translucent substrate and including a first phosphor and a first glass;
A second layer including a second glass provided to cover at least the upper surface of the first layer and having a higher softening point than the first glass;
With
The first phosphor is less prone to degradation when exposed to the softening point temperature of the first glass than when exposed to the softening point temperature of the second glass,
Optical component. The first phosphor has a heat resistant temperature higher than the softening point of the first glass and lower than the softening point of the second glass.
The optical component according to claim 1. The first phosphor is a non-oxide phosphor.
The optical component according to claim 1. The first phosphor is a nitride-based phosphor.
The optical component according to claim 1. The second layer includes a second phosphor having higher heat resistance than the first phosphor.
The optical component of any one of Claims 1-4. The second phosphor is an oxide phosphor.
The optical component according to claim 5. The second layer covers the upper surface and side surfaces of the first layer,
The optical component according to claim 1. The optical component according to any one of claims 1 to 7,
An optical component comprising a third layer that includes a third glass that is provided between the translucent substrate and the second layer so as to surround the first layer and has a softening point higher than that of the first glass. . The third layer includes the first phosphor.
The optical component according to claim 8. The glass is formed by baking white glass powder,
The optical component according to claim 1. (A) A first paste containing a first phosphor and a first glass is coated on a light-transmitting substrate, and the first paste is fired at a firing temperature corresponding to the softening point of the first glass. A layering process;
(B) applying a second paste containing a second glass having a softening point higher than that of the first glass so as to cover at least the upper surface of the first layer, and at a firing temperature corresponding to the softening point of the second glass; Baking the two pastes into a second layer;
Including
As the first phosphor, a phosphor that is less likely to deteriorate when exposed to the softening point temperature of the first glass than when exposed to the softening point temperature of the second glass,
Manufacturing method of optical components. After the step (a), a third paste containing a third glass having a softening point higher than that of the first glass is applied on the translucent substrate so as to cover a side surface of the first layer, A third layer forming step is performed by baking the third paste at a baking temperature corresponding to the softening point of the third glass to form a third layer, and then the step (b) is performed so that the second layer is Forming an upper surface of the first layer and the third layer;
The manufacturing method of the optical component of Claim 11.

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